[PATCH 25/27] HID: wacom: leds: fix ordering of LED banks

Benjamin Tissoires
2016-07-05T14:42:28Z

Historically, 21UX2 and 24HD have the select groups inverted
(0 is the right LED bank, and 1 the left one).

This is not right, so fix that in the new LED API. For backward
compatibility, we keep the wacom_led sysfs ABI stable. We don't
need to care about luminance for these two devices as only the
select sysfs file gets exported (brightness is not configurable).

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
drivers/hid/wacom_sys.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index b88896c..153e453 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -683,8 +683,10 @@ static int wacom_led_control(struct wacom *wacom)
int led = wacom->led.groups[0].select | 0x4;

if (wacom->wacom_wac.features.type == WACOM_21UX2 ||
- wacom->wacom_wac.features.type == WACOM_24HD)
- led |= (wacom->led.groups[1].select << 4) | 0x40;
+ wacom->wacom_wac.features.type == WACOM_24HD) {
+ led <<= 4;
+ led |= wacom->led.groups[1].select | 0x04;
+ }

buf[0] = report_id;
buf[1] = led;
@@ -742,6 +744,19 @@ out:
return retval;
}

+static inline int wacom_led_select_get_id(struct wacom *wacom, int set_id)
+{
+ /*
+ * Historically, 21UX2 and 24HD have the select groups inverted
+ * (0 is the right LED bank, and 1 the left one)
+ */
+ if (wacom->wacom_wac.features.type == WACOM_21UX2 ||
+ wacom->wacom_wac.features.type == WACOM_24HD)
+ return 1 - set_id;
+
+ return set_id;
+}
+
static ssize_t wacom_led_select_store(struct device *dev, int set_id,
const char *buf, size_t count)
{
@@ -754,6 +769,8 @@ static ssize_t wacom_led_select_store(struct device *dev, int set_id,
if (err)
return err;

+ set_id = wacom_led_select_get_id(wacom, set_id);
+
mutex_lock(&wacom->lock);

wacom->led.groups[set_id].select = id & 0x3;
@@ -775,8 +792,9 @@ static ssize_t wacom_led##SET_ID##_select_show(struct device *dev, \
{ \
struct hid_device *hdev = to_hid_device(dev);\
struct wacom *wacom = hid_get_drvdata(hdev); \
+ int set_id = wacom_led_select_get_id(wacom, SET_ID); \
return scnprintf(buf, PAGE_SIZE, "%d\n", \
- wacom->led.groups[SET_ID].select); \
+ wacom->led.groups[set_id].select); \
} \
static DEVICE_ATTR(status_led##SET_ID##_select, DEV_ATTR_RW_PERM, \
wacom_led##SET_ID##_select_show, \
--
2.5.5